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FLIP - Research Vessel

Key Data

FLIP ship

FLIP (Floating Instrument Platform) is the US Navy's oldest, and most unusual, research vessel.

Commonly referred to as the FLIP ship, it is actually a 355ft long, spoon-shaped buoy which can be flipped from horizontal to a vertical position by pumping 700t of seawater into the 'handle' end whilst flooding air into the 'cradle', causing it to rise up out of the sea.

Once the 28 minute transformation from horizontal to vertical has taken place, 300m of the buoy are submerged underwater, keeping the 700 long-ton mass steady and making it perfect for researching wave height, acoustic signals, water temperature and density, and for the collection of meteorological data.

FLIP was created in 1962 by scientists Dr Fred Fisher and Dr Fred Spiess, who wanted a more stable space than a conventional research ship to study wave forms. The build was funded by the US Office of Naval Research (who still own the buoy) and the Marine Physical Laboratory of the Scripps Institution of Oceanography (who still operate it) and launched by The Gunderson Brothers Engineering Company of Portland, Oregon.

FLIP was given a $2m makeover in 1995 and currently resides in La Jolla, California, although it operates all over the world. The buoy has so far completed over 300 operations.


The transformation from horizontal to vertical is one of the most impressive sights on the ocean. Because of the potential interference with the acoustic instruments, FLIP has no engines or other means of propulsion, so it has to be towed out to sea. In tow, FLIP can reach speeds of 7–10 knots.

"FLIP's unique design makes it the only vessel in the world capable of operating both horizontally and vertically."

When it has reached its desired location, it either drifts freely or is held in place using one or all of its three anchors. The long, thin end of the buoy has special ballast tanks, which are then flooded with seawater, causing it to sink, whilst air tanks cause the other end of the buoy to rise. The protruding end is equivalent in height to a five-storey building.

FLIP can operate equally well in shallow water or depths of over 2,000 fathoms. Once the 300ft of buoy is submerged the vessel is so stable it is almost unaffected by vertical wave motion.

A 30ft wave only causes FLIP to move three feet vertically in the water column. Although this is the size of wave the buoy was built to withstand, FLIP can cope swells of up to 80ft.

For FLIP to flip back to a horizontal position, air compressed into eight tanks is used to push the seawater out of the ballast tanks. The submerged end of FLIP rises until the buoy is once again level with the water.


FLIP's unique design makes it the only vessel in the world capable of operating both horizontally and vertically. Scientific instruments are built sideways into the wall so that as the buoy flips, the instruments flip into a usable position as well.

Most rooms on FLIP have two doors; one to use when horizontal, the other when FLIP is vertical. Bunk beds, toilets and stoves are built on swivels and gimbals, so they will turn along with the buoy, but things that would not rotate so well, like sinks, are built both horizontally and vertically in each room.

The main power source comes from two 150kW generators with one 40kW generator for backup. Navigation equipment includes a gyro, GPS and RADAR. Communication equipment includes HF, VHF, INMARSAT and cellular.


Life for the five crew members and 11 researchers who can live on-board FLIP at any one time is not for the faint-hearted. Stays in the cramped conditions last for 30–45 days and, during the flip, everyone has to stand on deck whilst the deck below them gradually becomes a bulkhead, before stepping onto a deck that was a bulkhead just minutes before.

"The last 15° of movement prior to arriving in the vertical happens quickly and is reasonably exciting as the exterior decks where everyone is positioned appear to be heading into the sea," says Captain William A Gaines, assistant director of Marine Physical Laboratory at Scripps Institution of Oceanography.

"The crew and riders remain on the external decks during the flipping evolution. The lowest exterior is about 15ft above the waterline when FLIP is in the vertical. There is lots of noise as the remaining air from the ballast tanks escapes from the vent lines located on the lowest external deck."

Once the transformation has occurred, staff have to cope with working five storeys above the ocean; contending with steep stairs, narrow booms and the confined spaces necessary to make FLIP operational.

"A 30ft wave only causes FLIP to move three feet vertically in the water column."

"The habitability conditions on FLIP at sea can best be described as austere," says Captain Gaines.

"Because of the combined spaces, there is limited privacy. There are two heads (bathrooms) onboard, two showers, but only one that can be used in the vertical and one that can be used in the horizontal. With 16 persons and one shower, Sunday showers are not permitted."

"It does take a special person to serve on FLIP. However, many scientists and science party members prefer conducting science from FLIP over being embarked in a conventional research ship because of the stability that FLIP offers. The small crew on FLIP creates a feeling of family and cohesiveness. The Officer in Charge of FLIP, Tom Golfinos, has been onboard for 17 years."

FLIP during the 28 minute flipping process, caught halfway between its horizontal and vertical position.
FLIP once the transformation has taken place, 300m of the buoy are underwater and the protruding part is as tall as a five-storey building.
FLIP before the transformation begins.
FLIP ship inventors Dr Fred Spiess and Dr Fred Fisher relax onboard the buoy.